Fact is that there is a huge paper trail of SBF's malfeasance, nevermind the fact that his co-conspirators appear to be turning against him. If anything, his interviews seemed to be his attempt to argue for negligence over malice in his case.
Yes, SBF is going to prison for a long time. No, I don't think anyone has made a viable argument that his interviews over the past few weeks are likely to make his sentence worse.